As sugar is among the principal foods for man and animals, as well as a commercially important food for fermentation organisms, much research is being devoted to raising the sucrose yield of sugarcane in a variety of ways. In recent years this research has increasingly turned toward a search for chemical agents which effectively enhance the ripening of sugarcane and do so in a manner which is both safe and economical.
Some of the more successful chemical ripeners for sugarcane so far discovered are disclosed in U.S. Pat. Nos. 3,224,865; 3,245,775; 3,291,592; 3,482,959; 3,482,961; 3,493,361; 3,505,056; 3,660,072 and 3,671,219. Still other chemical agents which have been found successful or shown promise as sugarcane ripeners, such as cyclo-leucine, anisomycin and cycloheximide, are disclosed, for instance, in Hawaiian Planters' Record, Vol. 58, No. 5, pp. 71-79 (1970).
As is evident from these prior disclosures, the more active ripeners differ widely from each other in terms of chemical structure as well as chemical and biological properties. In the search for effective ripeners failures continue to outnumber successes by a wide margin. Moreover, because of toxicological or ecological concerns and the consequent possibility that rotation of use of different chemical ripeners in consecutive seasons in a given area may be preferable to the continued use of a single ripener mixture, the search for new sugarcane ripeners continues unabated.
Generally speaking, chemicals selected for evaluation are those which have been previously found active in work with other plants as plant hormones, hormonal or non-hormonal herbicides, antifungal agents or antibiotics, growth inhibitors or, contrariwise, growth stimulants. However, among the compounds heretofore known to be useful for such other special and often contradictory purposes only an exceptional few are found to be effective in controlling the ripening of sugarcane in the desired manner.
No predictable relationship has yet been recognized between (a) the chemical structure of such compounds, (b) their phytotoxic effects, or (c) their physiological effects on the morphogenetic development of the plant, on the one hand, and their activity in having positive effects on ripening, on the other hand.